ESA's journey to the Moon continues

SMART-1 is travelling to the Moon using a new solar-electric propulsion system

12 January 2004

ESA's SMART-1 spacecraft is now in its 176th orbit, and is in good health with all functions performing well, on its long trek to the Moon.

The first major mission target, to leave the most dangerous part of the radiation belts which surround the Earth, has been achieved.

Between 23 December 2003 and 2 January 2004, the electric propulsion system ('ion engine') fired continuously for a record duration of more than 240 hours.

This is likely to remain the record for some time because, later in January, SMART-1 changes from continuous thrusting to more orbitally-efficient periodic firing.

The total cumulated thrust time so far is more than 1500 hours, and the engine has consumed 24 kilograms of xenon propellant gas. This has now raised the speed of the spacecraft to about 3850 kilometres per hour.

The spacecraft is travelling in a continuous spiral leading from one orbit to another, and it is currently passing closest to the Earth at about 20 000 kilometres, and travelling out to a distance of nearly 60 000 kilometres (its orbital period has almost been doubled from the initial 10 hours 41 minutes to the present 20 hours and 19 minutes).